Last Sunday's episode of King of the Hill, which either hasn't shown up yet on IMDB
or is an old rerun [update: the episode is up on TV.com], featured Bobby attending a Cotillion class, wherein the participants learn formal manners when interacting with members of the opposite sex. At one point, while teaching the young men how to help remove a woman's coat, the matronly instructor reminds the young ladies, "eye contact!" By which she means that they should maintain it.
Assuming that this particular aspect of Cotillion was well-researched, Mike Judge illuminated something I've been saying for a while: eye contact doesn't come naturally to young women. Which was why, in a more civilized age, it was taught to them as an element of good manners.